Roadway excavating machine



Aug. 16, 1938. J, Low n v 2,126,791

ROADWAY EXCAVATING MACHINE MTDIENEY Aug. 16, 1938. J. J. LOW

ROADWAY EXGAVATING MACHINE HTTRNEY 4 4 Sheets- Sheet 2 /NVENTo/a' /oH/v J. Low

Filed Deo. 18, 1955 Aug. 16,1938. l 1J. Qw 2,126,791

ROADWAY EXCAVATING MACHINE Filed Dec. 18, i955 4 Sheets-Sheet s ATTORNEY Allg. 16, v A \J. J. LOW v vROADWAY EXCAVATING MACHINE Filed Dec. 18, 1'935 4 Sheets-Sheet 4 /Ii//l//r/ lll 1 'l A |V////////////4 Q 'BY JoHNJ/vou/ 'Q l Patented Aug. 16, 1.938

PATENT oFFlcE ROADWAY EXCAVATING MACHINE John J. Low, Los Angeles, Calif., assignor to Kay Brunner Steel Products Inc., a corporation of Delaware Application December 1s, 1935, serial N0. 55,037

6 Claims.

My invention relates to roadway excavating machines oi' the character known as trail builders or bull dozers wherein excavating implements are carried and advanced by a tractor to move earth forwardly or to either side thereof in the formation of a roadway. In such machines mechanisms are provided for elevating the implements to facilitate movement of the machine as a whole from place to place, and to obtain vertical adjustments of the implements in respect to the ground in order that they may perform predetermined earth moving operations.

It is a purposeof my invention to provide such an elevating mechanism which embodies a lever system that produces a maximum leverage in respect to and when` the excavating implement is in its lowermost position of adjustment, so that when the implement is elevated from this position in which the load imposed thereon by the earth is the greatest, the maximum power of which the mechanism is capable is exerted to elevate the implement.

It is also a purpose of my invention to provide two such lever systems mounted on two supports independently movable vertically and operated by hydraulic rams interconnected to automatically balance or equalize the eiective levers of the two systems and thus at all times to maintain an equal distribution of pressure or lift throughout the length of the excavating implement in a manner to quickly restore the ends of the implement to the same level irrespective of the variation of load imposed by the earth upon which the implement is acting.

A further purpose of my invention is the provision in a roadway excavating machine of mountings for the pivoted frame of an excavating implement carried thereby, by which adjustments of the pivotal points of the frame can be made for the purpose of tilting the implement longitudinally to compensate for transverse tilting of the machine in a manner to maintain the implement horizontal. I

A further purpose of my invention is a provision in an excavating machine of a connector between the excavating implement supporting frame and the elevating mechanism therefor, which is characterized by the structure and relationship of its parts to withstand, without distortion, the severe srains` and stresses to which they are subjected when in use, and to thereby permit-ready detachability thereof when and as required to disconnect the frame from the elevating mechanism.

I will describe only one form of excavating machine for roadways, including one form o f elevating mechanism for the excavating implement thereof,` one form of pivotal mounting for the supporting frame of the excavating implement, and one form of connector, each embodying my invention, and will then point out the novel 5 features thereof in claims.

In the accompanying drawings:

Fig. 1 is a view showing in top plan one form of excavating machine for roadways embodying my invention.

Fig. 2 is a view showing the excavating machine in side elevation and illustrating in dash lines the uppermost position of the excavating implement and the mechanism by which it is elevated.

Fig. 3 is an enlarged vertical sectional View taken on the .line 3 3 of Fig. 2.

Fig. 4 is a horizontal sectional View taken on the line 4-4 of Fig. 2.

Fig. 5 is a view showing in elevation the rear end of one of the frame arms for supporting the excavating implement.

Fig. 6 is a vertical sectional view taken on the line 6-6 of Fig. 4. Y

Fig. 7 is a vertical sectional view taken on the line 1 1 of Fig. 4.

Fig. 8 is a vertical sectional view taken on the line 8-8 of Fig. 4. r

Fig. 9 is an enlarged vertical sectional view taken on the line 9-9 of Fig. 2.

Fig. 10 is an enlarged fragmentary sectional view of the fastener shown in Fig. 9.

Fig. 1l is a sectional view on a reduced scale and taken on a line II-H of Fig. 10.

Fig. 12 is an enlarged sectional view taken on the line l2-I2 of Fig. 2.

Fig. 13 is a sectional view taken on the line |3I3 of Fig. 12.

Fig. 14 is an enlarged sectional View taken on the line lll-I4 of Fig. 1.

In Figs. 1 and 2, I have shown my excavating machine incorporated in a conventional form of tractor, and to simplify the drawings only those parts of the tractor have been illustrated which are necessary to a clear understanding of my invention.- At each side of the tractor a pair of parallel spaced channel beams 20 and 2| constituting a tracklayer frame are arranged to form a support for a rear wheel (not shown) and a front wheel 22, and around these wheels extend an endless track 23. The wheel 22 is fixed to a shaft 24 journaled in bearings 25 carried by a pair of blocks 26 slidable on the beams 20 and 2l and urged forwardly by springs 21 to yieldably maintain the wheel 22 in such an advanced position as to keep the track 23 fully extended.

This construction and arrangement of elements allows the wheel 22 to yield rearwardly in the event a rock or other obstruction lodges between the wheel and the track, and in this manner the possibility is avoided of breaking the track as a result thereof.

The excavating machine embodying my invention is shown provided with a bull dozer as representing any form of road excavating implement adapted to be advanced by movement of the tractor to perform excavating operations in respect to a roadway. This bull dozer comprises a blade 39 secured to.a scoop 3|, while the latter in turn is secured to a cross member 32 fixed at its ends to a pair of arms 33. These arms and cross member constitute a frame which is pivotally supported on the tractor to permit adjustment of the bull dozer vertically upon the tractor.

By means of ears 34 fixed to the cross member 32 by pins 35 extending through the ears and the arms 33, the cross member is secured to the arms. Brace bars 39 are secured to the upper edge of the cross member and to the arms for bracing the cross member, as will be understood. The arms 33 extend rearwardly to opposite sides of the tractor and each arm is hollow and preferably of angular form in cross section, as best shown in Fig. 3.

Into the open rear end of each arm 33 is pro- Jected and suitably secured an extension 31 of a block for a pintle 38. The block is made up oi' one bearing part 39 formed integral with the extension 31 and provided with a slot 40 of T- form in which is received another bearing part 4I. By means of a boltl 42 extending through both bearing parts the bearing part 4| is securely clamped in such position within the bearing part 39 as to form a bearing for the pintle 38, the pintle being confined within the block by a collar 43.

'I'he pintle 38 is fixd to one end of a bracket 44, and the bracket in turn is mounted on a pin 45formed on a boss 415l of a support 48, the bracket being conned on the pin by means of a screw 41. The support 45 is secured by screws 49 to a plate 49 which is welded or otherwise secured to the outer beam 20. As best shown in Figs. 'l and 8, the support 46 is formed with an extension 50, and the bracket with an extension i formed with an arcuate slot 52.

A screw 53 vcarrying a washer 54 extends through the slot 52 and is threaded in the extension 58' for clamping the extension 5| to the latter. 'I'he confronting faces of the two extensions are serrated or otherwise roughened to lock the extension 5I against movement once it is clamped by the screw. In this manner the bracket can be secured in any desired position of adjustment about the pin 45 as a center to secure the pintle in any vertical position of adjustment.

Manifestly, the blocks, pintles and brackets provide mountings for pivotally supporting the frame arms 33 on the tractor, which are adjustable to lower or raise the pivotal support for either arm. By such adjustment the bull dozer can be tilted from end to end in either direction longitudinally to cause it to occupy such a predetermined angular position with respect to the tractor as to assume a horizontal position where the roadway which the tractor is traversing is inclined to one side or the other and it is desired to level it, or where the earth is softer on one side of the roadway than on the other to cause the tractor to tilt transversely. Thus by maintaining the bull dozer in a horizontal position the roadway worked by the bull dozer or other excavating implement will, in consequence, be formed horizontal transversely.

Referring again to Figs. 1 and 2, the bull dozer carrying frame is adapted to be swung upwardly about its pivots 33 for effecting vertical adjustments of the bull dozer in order that the latter may perform predetermined earth moving operations under forward movement of the tractor, as well as to permit movement of the entire machine from place to place. For this purpose two mechanisms are provided, although a single mechanism may be employed but .with less advantages. As the two mechanisms are identical in construction and operation, a description of one will suillce for both.

As shown in Fig. 3, a bridge member 55 is provided wlth feet 56 secured on the respective beams and 2l. To this bridge member are bolted a pair of brackets 51 having pins 58 upon which are mounted the rear ends'of a pair of arms 59, the arms being confined on rthe pins by reduced and threaded bosses 60 having nuts 5I and washers 62 thereon.

As shown in Figs. 2 and 3, the arms 59 form the lower part of a frame F, while two arms vlill form the upper part of the frame. Both pairs of arms are triangular inform with their wide ends confronting, and each arm 59 and the respective upper arm 84 are yformed integral with each other. At the junction of the arms 59 and 64, they are braced transversely by bosses 65 through which a pair of bolts 86 extend to support a filler bar 51 thereon between the hubs. From this point forwardly the arms 64 converge to a transverse brace 61 secured by a bolt 61h, and from then on they are parallel. At their forward ends they are formed with bosses 68 through which a bolt 69 extends to support a hub 19 of a bell-crank lever B. This lever B is formed with a short lever arm 1|a and a long lever arm. 1Ib disposed at an acute angle thereto, and with a brace 1I connecting the two. The bolt 69 in extending through the hub 10 provides a fulcrum for the lever from which it is suspended for oscillating movements at the forward end of the frame F.

' To the forward end of the long lever arm 1lb is secured a pair of plates 12 in which a lpair of trunnions 13 (Fig. 12) of a head 14 are secured to provide a pivotal connection between the lever and a rod 15. This rod is slidable in the head 14 and confined against downward displacement by a nut 16. The lower end of the rod extends into a sleeve 11, and is secured therein for longitudinal adjustment by means of a bolt 18 which is extendable through any one pair of a plurality of pairs of openings 19 in the sleeve. The sleeve 11 has a clevis 80 formed integral therewith for connection with another clevis 8| bolted to a con- .necting bar 82. Bolts 83 and 84 and a block 84a 'are associated with the clevises in the manner shown in Figs. 12 and 13 to provide a universal joint between two.

Mlanifestly the rod 14, the sleeve 11, andthe appurtenant elementsl constitute an extensible link, indicated generally at L, for operatively connecting the lever B to the connecting bar 82. By means of a coiled spring 15a surrounding the rod betweenthe head 14 and a fixed collar 15b, the head is yieldably urged against the nut 16 to allow the rod to move upwardly through the head when for any reason sufficient upward pressure is exerted .on the rod to overcome that of the spring. In this manner the link normally is caused to remain extended for movement by and with the lever B. However, should the link be forced upward when the lever is secured in any position of adjustment, the link will move relative to the lever and thus prevent possible breakage of the lever and frame. Such upward movement of the link occurs when the bull dozer in its forward movement, is suddenly elevated by passing over a rock or other road obstruction.

The connecting bar 82 for each mechanism is connected at its ends to the cross member 32 and the respective frame arm 33, so as to extend obliquely between the two, as shown in Fig. l. It is by means of these two bars that the entire bull dozer carrying frame is connected to the two elevating mechanisms therefor. I n order to permit this frame to be readily detached from the bars 82 and thus allow the substitution of another form of excavation implement, such as a trail builder for example, the bars at 'their ends are secured detachably to both the cross member 32 and the arms 33 by connectors K. Each connector is characterized by its ability to withstand without distortion of its parts, the

severe strains and stresses to which it is subjected in actual use by reason of the movements between the bull dozerframe and the bars, and to thereby permit ready disconnection of the frame from the bars when required.

The connectors K are of like construction, and as shown in Fig. 14 each connector comprises spaced ears 85 on the end of the bar 82, between which are received spaced ears 88 of a bracket 81. The bracket 81 is suitably ilxed to the cross member 32 or the frame arm 33, as the case may be. The openings in the ears 85 are tapered as shown to receive the tapered portions of plugs 88, while the openings in the ears 86 are of uniform diameter to receive the corresponding portions of the plugs. Through the plugs extends freely a connecting pin or rod 89 having nuts 90 and washers 9| on its ends to confine the pin against displacement.

Thus, through coaction of thepin and plugs the ears for the bar and bracket are pivotally connected one to the other, and all stresses to which the connector is subjected when in use, are imposed on the ears and plugs, rather than on the pin so that the latter can not be bent or otherwise distorted by reason thereof. Manifestly, by preserving the rectilinear contour of the pin it can, at all times, be removed readily to permit disconnection of the bar from the bull dozer carrying frame. Also the tapered form of the plugs prevents them from jamming within the ears so that they can be removed easily when required; and any Wear between the ears and the plugs can be taken up by inward adjustment of the nuts.

Referring now to Figs. 1, 2, and 9, each frame F is supported in elevated position by a pair of ears 92 fixed on the arms 59 and pivoted by pins 93 on a pair of uprights 94. These uprights are supported for pivotal movement on pintles 95 and 95, respectively, extending into hubs 96 integral with the uprights. The pintles are formed integral with plates 91 secured to the sldingblocks 26 by bolts 98 which extend through the blocks and inner plates 99. The lower ends of the uprights are formed with lateral enlargement |00, which bear against the lower edges of the beams 20 and 2| for bracing the uprights laterally inward.

From the preceding description, it will be clear that the uprights are pivotally supported on the blocks.26,`and as these blocks can and do slide rearwardly on the beams 20 and 2| when an obstruction becomes interposed between the tractor wheel and the track, the uprights will, as a consequence, move rearwardly with the blocks. The rpivotal mountings 93 and 95, 95 permit of such movement of the uprights without disturbing to any appreciable degree, the vertical position of the frames F, F, and hence the positions of the fulcrums 89. Thus, the uprights serve to properly support the frames on the tractor beams without interfering with the functioning of the blocks and springs.

The inner pintle 95s` is threaded to receive la nut |0| with a washer |02 therebeneath, for confining the respective uprights 94 against displacement from the pintle. As best shown in Figs. 10 and l1, the outer pintle 95 is constructed to permit itsextensioninto the opening |03 of a wear plate |04. This plate is secured to the outer 'side of the inner upright 94 by bolts |05, the heads of which are flush with the outer surface oi' the plate.

To prevent displacement of the hub 96 from the pintle 95 the end of the pintle which terminates flush with the outer surface of the wear plate is formed with an annular groove |08 in which a two part ring |01 is received. This ring is also grooved to receive a circular wire spring |08 which operates to clamp the ring parts in the pintle groove. As the ring is of a diameter to abut the upright within the plate opening |03, it becomes apparent that the ring serves to lock the upright against displacement from the pintle.

'I'he wear plate |04 is provided to protect the outer upright against wear due to rubbing thereagainst of the frame arm 33, and it will be understood that in actual use the frame arm does move laterally as well as vertically. A wear plate |09 is secured to the arm 33, as shown in Fig. 9, to protect the arm itself against wear, and this plate is curved vertically to allow for twisting movements of the arm which occur when in use. Thus, both the frame arm and upright are adequately protected against wear and the resultant weakening of these parts.

Referring again to Figs. 1 and 2, and to the mechanisms for elevating the bull dozer, each mechanism includes as an actuator a hydraulic ram, the cylinder ||0 of which is provided at its rear end with an ear pivoted on the filler bar 61 so that the cylinder can swing about the` bar as a center. The piston (not shown) in the cylinder has a rod ||2 which is pivotally connected, as at H3, to the lower end of the short lever arm 1|. Fluid` pressure is supplied to either end of the cylinder through conduits ||4 which extend rearwardly on the tractor to a fluid pressure pump ||5. The passage of the fluid to both cylinders is manually controlled through suitable valves (not shown) operable by movement of a lever |B to supply iluid simultaneously at the same pressure to both of the cylinders.

In the operation of the two elevating mechanisms movement of the piston rods |2 forwardly from the positions shown in Fig. 2 swings the levers B upwardly about the fulcrums 69 thereby elevating the links L to swing the bull dozer frame upwardly about the pivots 38. In this manner, depending upon the pressure of fluid supplied to the-pistons, the bull dozer can be elevated to any vertical position of adjustment desired.

As illustrated in` Fig. 2, the bull dozer is in its'lowest position of adjustment, wherein the pivot III for each piston rod is perpendicular to the lever fulcrum B9, and the rod Il! is at right angles to the short lever arm 'Il'. Manifestly, the effective leverage of the short lever arm is now the greatest, and thus the power delivered to the bull dozer by the rams is always the greatest when the bull doaer is in its lowermost position. It is in this position of the bull dozer that the greatest load is imposed thereon by the earth on which it is acting, because the depth of penetration thereof is the greatest.

As the levers B move upwardly from this lowermost position the effective leverage of the short lever arm decreases, and thus the lifting force applied to the bull dozer likewise decreases. However, it will be understood that as the bull dozer is elevated it is withdrawn from the earth which it is moving or has moved, therefore, the load imposed thereon is gradually removed, so

.that the power required to elevate the bull dozer is correspondingly lessened.

Although a single elevating mechanism may be employed in a manner to produce maximum leverage and, hence, maximum lift when the bull dozer is in its lowest position of adjustment, by

theprovision of two such mechanisms the following additional advantage is attained. Let it be assumed that a greater load of earth is imposed on one end of the bull dozer than on the other. This causes the frame of the bull dozer to be twisted or sprung to such a degree as to cause tilting of the bull dozer proper with the heaviest end lowermost.

Under such a condition that lever B connected to the lowermost end of the bull dozer will, when elevating the latter, exert a greater lift than the lever connected to the upper end of the bull dozer. As a consequence, an equalizing lifting effect is produced to restore the bull dozer to a horizontal position, that is, to lift the lower end of the bull dozer more rapidly than the upper end until the two ends are at the same level. Once this condition is reached the twisting strains to which thebull dozer frame has been subjected are removed, and from then on the bull dozer is elevated evenly from end to end.

By incorporating in each of the two elevating mechanisms a hydraulic ram and connecting the two rams to the pump so that there is an equal distribution, of pressure to the rams, the rams constantly tend to exert on the implement through the levers the same degree of lift. Through provision of the two leverage systems and the resultant decrease in the eective leverages as the implement is elevated. more rapid equalization of the fluid pressures as delivered to the ramsis effected to accelerate return of the bull dozer to horizontal position.

It is important to note that the frames F as well as the beams 33 are mounted on the tracklayer frames so that their weight as well as any load of earth imposed on the bull dozer, is borne by the tracklayer frames and not by the tractor frame. Obviously, this increases the traction between the tracks and the ground. Inasmuch as the frames F support the two elevating mechanisms for the bull dozer, and the frames in turn are supported on the tracklayer frames which latter are movable on the tractor frame and, hence, movable relatively in vertical planes, it will be manifest that the fulcrums 69 for the levers B are variable vertically with movements of the tracklayer frames.

By virtue of the fact that the rams are mounted on the frames F and are ilexibly connected one to the other, the necessity is eliminated of a mechanical connection between the two leverage systems to effect a leverage balance as has been the practice heretofore.

I claim:

1. In a roadway excavating machine having a tractor provided with beams arranged in pairs f at opposite sides thereof, blocks mounted on the beams for movement lengthwise thereof, wheels mounted on the' blocks, endless tracks trained about the wheels, springs for yieldabiy urgingthe blocks to maintain the tracks in driving relation to the wheels, an excavating implement mounted on the tractor for upward movement thereon; and a pair of mechanisms for elevating the implement, each comprising an inclined frame mounted at its lower end on the respective pair of beams, uprights pivoted on the frame and on the blocks to support the frame in inclined position irrespective of the position of the blocks, a

, bell-crank connected to the respective ends of the implement, and an actuator for the bell-crank mounted on the frame.

2. In a roadway excavating machine having a tractor provided with wheels and endless tracks trained about the wheels, means for supporting the wheels on the tractor for yielding movement relative to the tracks in the event an obstruction lodges between the wheels and tracks, an excavatingl implement mounted on the tractor for upward movement, a pair of'frames pivoted at onev end on the tractor, uprights pivoted on the frames between theirends and pivotally supported on said means to support the frames in inclined positions on the tractor irrespective of the position of the wheels on the tractor, mechanisms mounted on the upper portions of the frames and operatively connected to said implement for elevating the latter, and actuators mounted on the frames for operating the mechanisms.

3. In a roadway excavating machine having beams at opposite sides thereof; an implement supporting frame of U-form having its ends pivoted on said beams; pintles carried by the beams; uprights pivoted on the pintles; wear plates secured to the uprights and having openings therein for receiving the pintles and to expose therein portions of the uprights; and means on the pintles within said openings abutting the uprights for securing the uprights against displacement from the pintles. 4. In combination; a tractor having tracklayer frames; front and rear wheels supported on the frames; means for supporting the front wheels for yielding movement rearwardly on the frames; a pair of arms pivoted on the tracklayer frames; an implement secured to said arms in advance of the tractor; a pair of supporting frames pivoted on the tracklayerzframes; a pair of bellcrank levers fulcrumed on the supporting frames and operatively connected to said implement; means for so mounting the supporting frames on said supporting means that irrespective of the position of the front wheels on the frames the positions of the lever fulcrums will remain xed relative to the frames; and means for actuating said levers.

5. A combination as embodied in claim 4 wherein the means for mounting the supporting frames on said supporting means comprises uprights pivoted on. the supporting frames and on the supporting means.

6. In combination; a tractor having a pair of independently vertically movable track frames;

amener an excavating implement pivoted for vertical movement on the track frames; a pair of lever systems mounted respectively on the track frames and operably connected independently to said implement; and hydraulic rams, one for each of the lever systems for actuating the latter and interconnected hydraulically to equalize the eiective leverages of the two systems to maintain an equal distribution of pressure or lift throughout the 10 length of said implement, said systems having levers so mounted and so connected to said rams and implement that the eiective leverages thereof, as exerted on the implement, increase as the implement is lowered and decrease as the implement is elevated, whereby the ends of the implement when at different levels are rapidly restored to the same level with elevation of the implement and the hydraulic pressures of the rams rapidly equalized.

JOHN J. LOW. 

